Vildan Yayla

Excitability of facial nucleus and related brain-stem reflexes in hemifacial spasm, post-facial palsy synkinesis and facial myokymia

OBJECTIVE To compare the electrophysiological excitability characteristics of the facial nucleus and related structures in hemifacial spasm (HFS), post-facial palsy synkinesis (PFPS) and facial myokymia (FM). METHODS Facial F-waves, blink reflex recoveries and magnetically elicited silent periods (SP) were prospectively studied in 17 HFS, 17 PFPS, 8 FM cases and in 13 controls. Earlier unpublished observations on abnormal impulse transmission in 36 HFS and 29 PFPS cases were also included. RESULTS Enhanced F-waves were recorded on the symptomatic side in PFPS and HFS cases with a tendency to be more pronounced in PFPS. HFS and PFPS groups both showed an earlier blink reflex recovery, more prominent in PFPS patients, when stimulated and/or recorded on the symptomatic side. Unelicitable SPs were encountered after 24/39 stimulations in 5 patients with PFPS and rarely in HFS cases. Duration of elicitable SPs did not change remarkably. FM group had similar characteristics as normal controls in the 3 electrophysiological tests. Latencies of the lateral and synkinetic spread responses were significantly prolonged in the earlier PFPS group as compared to HFS. In two-point stimulation, both groups showed a greater latency shift in late responses, again more pronounced in PFPS. CONCLUSIONS PFPS and HFS cases had similar enhanced excitability patterns at the facial nucleus and related brain-stem structures, more marked on the symptomatic side and more obvious in the PFPS group. Findings elicited in the FM group were thought to be caused by asynchronous hyperactivity of facial motoneurons. SIGNIFICANCE In this comparative electrophysiological study, similar excitability patterns were found in HFS and PFPS groups, albeit with different intensities.

Childhood trauma and dissociation in tertiary care patients with migraine and tension type headache: A controlled study

OBJECTIVE The aims of this study were: i) to compare the severity of somatoform and psychoform dissociation and childhood trauma among migraine patients, tension-type headache patients (TTH), and healthy controls; and, ii) to identify any relationships between headache characteristics and dissociative symptoms and traumatic childhood experiences among tertiary care patients with headache. METHODS The study sample consisted of 79 patients with migraine, 49 patients with TTH and 40 healthy controls. They completed the socio-demographic form, Childhood Trauma Questionnaire (CTQ), Dissociative Experiences Scale (DES), and the Somatoform Dissociation Questionnaire (SDQ). RESULTS The average score for childhood emotional abuse was significantly higher in the TTH and migraine patients than in healthy controls; mean scores for emotional neglect and physical abuse were higher in TTH patients than healthy controls; and the total CTQ score was higher in TTH patients than in either migraine patients or healthy controls. Average DES scores were significantly higher in TTH patients versus migraine patients and controls; and SDQ scores were higher in both headache groups than in controls. Headache duration and severity were found to be significantly related to childhood abuse scores among migraine but not TTH patients. CONCLUSION Our findings support the evidence of a relationship between childhood trauma and migraines, and suggest that childhood traumatic events are common and deleteriously effect migraine characteristics. Also our study suggests that childhood trauma may have a role in TTH. Significant differences in the DES and SDQ scores between groups may be explained by the differences in childhood trauma experiences.

Rhinologic evaluation in patients with primary headache.

Objectives: In subjects with primary headaches, rhinologic pathologic condition may be associated with treatment refractoriness. In some cases, surgical correction of intranasal pathologic condition may decrease medication use. We aimed to evaluate the benefits of a rhinologic perspective in primary headache subjects by using neurologic management. Methods: Subjects with primary headache were examined by a neurologist and otolaryngologist. Initially, neurologic assessment was made, and medication was started. Migraine symptoms and pain severity were recorded using the Migraine Disability Assessment Scale and a 0 to 10 visual analog scale (VAS). Subjects pain severity of tension type headache was evaluated by VAS. Direct otorhinolaryngologic history of all primary headache subjects was taken, and they all underwent physical examination, rigid nasal endoscopy, sinus computed tomography, and mucosal contact point test. All examination and radiologic findings were noted. Subjects were separated into groups after 1-month medical neurologic management. Results: One hundred nine subjects were enrolled. Ninety-nine subjects completed follow-up. Seventy-eight percent of the subjects were women. The mean age was 33.6 years (range, 18-63 y). Twenty-six subjects had no significant intranasal pathologic condition (group 1). Twenty subjects had an intranasal pathologic condition but responded to the neurologic treatment (group 2). Fifty-three subjects had an intranasal pathologic condition, and the neurologic treatment failed for these 53 subjects. Surgical intervention was planned for these 53 subjects (group 3). Thirty-eight subjects accepted the operation (group 3a), and 15 subjects refused the surgical intervention (group 3b). All subjects Migraine Disability Assessment Scale and VAS scores were compared. A total of 73 subjects had rhinologic abnormalities. Groups 1 and 2 benefited from the neurologic treatment, but headache severity of group 3a reduced after rhinologic surgery. Group 3b who rejected surgical intervention did not respond to the neurologic treatment. Conclusions: This study describes a series of subjects presenting with various primary headaches who also have underlying rhinologic abnormalities. Surgical treatment of the underlying rhinologic pathologic abnormalities had a beneficial effect on headache.

Cortical excitability in Duchenne muscular dystrophy

OBJECTIVE To investigate the probable cortical excitability changes in DMD by electrophysiological means. METHODS Sixteen cases with DMD, 10 age-matched control children (CC) and 10 healthy adult volunteers (AC) were studied with a transcranial magnetic stimulation (TMS) test battery composed of central conduction time, cortical silent period and paired TMS paradigm. RESULTS There were no significant differences between DMD and CC groups except for lower amplitude motor responses in DMD cases. These two groups showed a similar pattern of excitability with less short interval intracortical inhibitions and shorter silent period durations as compared to the AC subjects. CONCLUSIONS The electrophysiological tests performed in our DMD patients did not reveal abnormalities caused particularly by the disorder. SIGNIFICANCE TMS excitability studies performed in DMD boys may not provide findings other than those related to the developmental age.

Excitability changes at brainstem and cortical levels in blind subjects.

OBJECTIVES This study was designed to search potential changes in trigemino-facial system in blind subjects by the use of relatively well-established electrophysiological methods. Excitability changes in the motor cortex were also investigated by transcranial magnetic stimulation studies (TMS) with the expectation of finding some abnormal interactions between the cortex and brainstem. METHODS Twenty blind (BS) and 13 control subjects (CoS) were included in the study. Blink reflex and its recovery with paired electrical stimulation were studied at 150, 200, 300, 400 and 500 ms interstimulus intervals (ISI). Facial F waves elicited by buccal branch stimulation were recorded from nasalis muscles. Motor cortex excitability with recordings from left first dorsal interosseus muscle was studied by using magnetically elicited silent periods and paired magnetic stimuli, subthreshold conditioning and suprathreshold test, given at ISIs of 2, 3, 4, 10, 12, 15 and 20 ms. RESULTS Blink reflex recovery was significantly reduced in BS group comparing to CoS at 400 and 500 ms ISIs. This difference between the groups was more prominent for the responses evoked by the initial stimulation side and faded away with stimulations on the contralateral side. Facial F wave amplitudes and F/M amplitude ratios were higher in BS group. In TMS studies, the early inhibitions at 2 and 4 ms were found to be significantly less in BS as compared to that of CoS. CONCLUSIONS The reduced blink reflex recovery and its fast restoration with continuing stimulation might be explained by conditioning and extinction processes which have been shown to be mainly carried out by cerebellar-brainstem pathways. Our TMS studies showed reduced intracortical inhibition in the motor cortices of BS cases and facial F wave studies revealed the possible effect of this altered excitability on the facial motor nuclei. SIGNIFICANCE Firing probabilities of facial motor neurons in BS are probably determined by the equilibrium between the low-set excitability of blink reflex interneurons and the enhanced excitability brought on by the descending motor pathways.

MRI findings and cognitive functions in a small cohort of myotonic dystrophy type 1: Retrospective analyses.

Myotonic dystrophy type 1 (DM1) is a progressive multisystemic disease with common cognitive deficits and potential brain involvement in addition to the cardinal muscular and systemic symptoms. Impaired mental function associated with nonspecific pathological findings such as white-matter hyperintense lesions (WMHLs), ventricular enlargement and brain atrophy on brain MRI have been previously reported in DM1 patients. While some studies showed correlation of brain morphological changes with neuropsychological and clinical parameters including CTG repeat sizes and disease severity scales in DM1, others failed. The goal of this study was to retrospectively investigate cranial MR abnormalities, predominantly WMHLs, and their effects on clinical and cognitive deficits in a small, phenotypically or genotypically well-characterized cohort of DM1 patients.

The Role of Patent Foramen Ovale in Cryptogenic Stroke

INTRODUCTION Almost one-third of ischemic strokes has an unknown etiology and are classified as cryptogenic stroke. Paradoxical embolism because of a patent foramen ovale (PFO) is detected in 40%-50% of these patients. Recently, PFO has been reported as a risk factor for patients of all age groups. METHODS In this study, 1080 ischemic stroke patients admitted to our clinic (2011-2013) were retrospectively evaluated. Age, sex, risk factors, complete blood count, vasculitis, biochemical and hypercoagulability tests, magnetic resonance imaging, magnetic resonance angiography, transthoracic echocardiography, transeosophageal echocardiography (TEE) findings, and therapeutic approaches were evaluated. RESULTS The age range of the participants (seven male and four female patients) was 20-60 years (mean=43.09±11.13 years). Hemiparesis (n=10), diplopia (n=2), hemianopsia (n=2), and dysarthria (n=2) were the main findings of the neurological examinations. Patient medical history revealed hypertension (n=3), asthma (n=1), deep venous thrombosis (n=1), and smoking (n=4). Diffusion-weighted imaging showed middle cerebral artery (n=8) and posterior cerebral artery (n=3) infarctions. In one case, symptomatic severe carotid stenosis was detected. In eight cases, TEE showed PFO without any other abnormalities, but PFO was associated with atrial septal aneurysm in two cases, and in one case it was associated with ventricular hypokinesia and pulmonary arterial hypertension. Antiplatelet therapy was applied to nine patients and percutaneous PFO closure operation to two patients. In a 2-year follow-up, no recurrent ischemic stroke was recorded. CONCLUSION PFO, especially in terms of the etiology of cryptogenic stroke in young patients, should not be underestimated. We want to emphasize the importance of TEE in identifying potential cardioembolic sources not only in young but also in all ischemic stroke patients with unknown etiology; we also discuss the controversial management options of PFO.

Motor unit number estimation in facial paralysis.

The value of motor unit number estimation (MUNE) in determining the prognosis of acute peripheral facial paralysis (PFP) was evaluated in 89 patients with PFP on days 6, 8, 11, 14, 20, and 30 of PFP and repeated once per month until complete recovery or the end of the first year. The symptomatic/asymptomatic side ratios of the compound muscle action potential (CMAP) amplitudes recorded from nasalis muscles and MUNEs studied using the incremental method by recording from the same muscle were assessed with regard to three outcome groups (Group I, complete recovery; Group II, mild dysfunction; Group III, moderate–moderately severe dysfunction). CMAP and MUNE ratios were parallel to each other in all patient groups throughout the observation period with lower values in the more severe groups. However, CMAP amplitude loss was significantly greater than the MUNE loss in the first 3 weeks of PFP. The MUNE method is not superior to CMAP size in determining prognosis in PFP. However, the significant disparity between the CMAP and MUNE ratios in the early period may have some physiological relevance with regard to the pathophysiology of the Wallerian degeneration process and deserves further research into its potential sources. Muscle Nerve 38: 1420–1428, 2008

Motor unit number estimation in transected peripheral nerves

Abstract Objectives: To study motor unit number estimation (MUNE) in acutely transected peripheral nerves, and to retest our previous observation which had revealed a discordance between the loss of compound muscle action potential (CMAP) size and decrease in MUNE during Wallerian degeneration. Methods: In eight patients with nine transected median or ulnar nerves, a total of 18 electrophysiological studies were performed before the complete nerve degeneration ensues. CMAP recordings and incremental MUNE studies were performed by stimulation of the nerves at the wrist level and recording from the appropriate hand muscles. The same studies repeated on the contralateral side. Results: Injury side to intact side ratios of the MUNEs were significantly higher than the CMAP ratios. Mean step areas in MUNE studies were found to be lower on the transected sides after 72 hours post-injury. Discussion: These findings support the existence of an electrophysiologically observable asynchrony in neuromuscular synapse dysfunction during Wallerian degeneration.

Perineural dexmedetomidine effects on sciatic nerve in rat

The present study was designed to test the hypothesis that high dose dexmedetomidine would increase the duration of antinociception to a thermal stimulus in a rat model of sciatic nerve blockade without causing nerve damage. The rats were anesthetized with isoflurane. After electromyography (EMG) recordings, right sciatic nerves were explored and perineural injections were delivered: Group D (n=7), 40μgμgkg-1 dexmedetomidine administration, Group II (n=6), (0.2mL) saline administration, Group III (n=2), only surgically exploration of the right sciatic nevre. Time to paw withdrawal latency (PAW) to a thermal stimulus for both paws and an assessment of motor function were measured every 30min after the nerve block until a return to baseline. The compound muscle action potential (CMAP) of right and left sciatic nerves were recorded 10 times per each nerve once more after perineural injections at 14 day. After EMG recordings, right and the part of left sciatic nerve were excised at a length of at minimum 15mm for histopathological examination. Comparison of right/left CMAP amplitude ratios before and 14 days after the procedure showed a statistically significant difference (p=0.000). There were no differences in perineural inflammation between the Group D, Group S, and Group E at 14 days.